Relative rates of $B$ meson decays into $psi_2S$ and $J/psi$ mesons

Abstract

We report on a study of the relative rates of B meson decays into psi(2S) and J/psi mesons using 1.3 fb^-1 of pbar p collisions at sqrt(s) = 1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe the channels B^0_s -> psi(2S)phi, B^0_s -> J/psi phi, B^_s16/- -> psi(2S) K^_s16/-, and B^_s16/- -> J/psi K^_s16/- and we measure the relative branching fractions for these channels to be B(B^0_s -> psi(2S)phi)/B(B^0_s -> J/psi phi) = 0.55 _s16/- 0.11 (stat) _s16/- 0.07 (syst) _s16/- 0.06 (B), B(B^_s16/- -> psi(2S) K^_s16/-)/B(B^_s16/- -> J/psi K^_s16/-) = 0.65 _s16/- 0.04 (stat) _s16/- 0.03 (syst) _s16/- 0.07 (B) where the final error corresponds to the uncertainty in the J/psi and psi(2S) branching ratio into two muons.